A function
The derivative remains the same, but we will need to take partial derivatives with respect to each single variable.
Which leads to
This means that there is an open disk centered at
This is completely reconstructed, it is probably inaccurate.
Recap on how to compute domains of everything is needed.
You cannot just square both sides of an inequality LOL
For the first one:
or
Limit exists when both left limit and right limit exist. So if from different directions the limit approaches the same value.
wip
The limit does not exist, since it depends on the particular direction we are considering.